CA1091292A - Engine timing control circuit - Google Patents
Engine timing control circuitInfo
- Publication number
- CA1091292A CA1091292A CA292,986A CA292986A CA1091292A CA 1091292 A CA1091292 A CA 1091292A CA 292986 A CA292986 A CA 292986A CA 1091292 A CA1091292 A CA 1091292A
- Authority
- CA
- Canada
- Prior art keywords
- engine
- signal
- integrator
- engine control
- crankshaft
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02P—IGNITION, OTHER THAN COMPRESSION IGNITION, FOR INTERNAL-COMBUSTION ENGINES; TESTING OF IGNITION TIMING IN COMPRESSION-IGNITION ENGINES
- F02P5/00—Advancing or retarding ignition; Control therefor
- F02P5/04—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions
- F02P5/145—Advancing or retarding ignition; Control therefor automatically, as a function of the working conditions of the engine or vehicle or of the atmospheric conditions using electrical means
- F02P5/155—Analogue data processing
- F02P5/1551—Analogue data processing by determination of elapsed time with reference to a particular point on the motor axle, dependent on specific conditions
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B75/00—Other engines
- F02B75/02—Engines characterised by their cycles, e.g. six-stroke
- F02B2075/022—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle
- F02B2075/025—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle two
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/40—Engine management systems
Landscapes
- Engineering & Computer Science (AREA)
- Signal Processing (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Electrical Control Of Ignition Timing (AREA)
- Ignition Installations For Internal Combustion Engines (AREA)
- Combined Controls Of Internal Combustion Engines (AREA)
Abstract
ENGINE TIMING CONTROL CIRCUIT
ABSTRACT OF THE DISCLOSURE
A pick-up provides a square wave signal whose period corresponds to 720°/N where N is the number of engine cylinders for a four stroke, two cycle internal combustion engine. An integrator is reset by both positive-going and negative-going edges of said square wave signal to produce a sawtooth waveform having a period equal to 360°/N. A blanking circuit which is coupled with the pick-up blanks the sawtooth waveform of said integrator during said alternate half cycles of the square wave. The blanked sawtooth waveform is supplied to one input of a comparator and a desired timing signal to the other input of said comparator. The comparator provides an engine timing signal when a predetermined relationship between the blanked sawtooth signal and the desired timing signal is attained. In this way, the engine timing signal is given once per cycle of said blanked sawtooth waveform with the timing thereof relative to said square wave being determined by the desired timing signal The preferred embodiment discloses a four cylinder engine con-figuration with electronic spark timing control.
ABSTRACT OF THE DISCLOSURE
A pick-up provides a square wave signal whose period corresponds to 720°/N where N is the number of engine cylinders for a four stroke, two cycle internal combustion engine. An integrator is reset by both positive-going and negative-going edges of said square wave signal to produce a sawtooth waveform having a period equal to 360°/N. A blanking circuit which is coupled with the pick-up blanks the sawtooth waveform of said integrator during said alternate half cycles of the square wave. The blanked sawtooth waveform is supplied to one input of a comparator and a desired timing signal to the other input of said comparator. The comparator provides an engine timing signal when a predetermined relationship between the blanked sawtooth signal and the desired timing signal is attained. In this way, the engine timing signal is given once per cycle of said blanked sawtooth waveform with the timing thereof relative to said square wave being determined by the desired timing signal The preferred embodiment discloses a four cylinder engine con-figuration with electronic spark timing control.
Description
l~9i'~
~ BACKGROUND AND SUMMARY OF THE INVRNTION ~ ¦
: ~ - This invention pertains generally to electronic eng~ne ¦ .
control Systems and specifically to a novel electronic circuit for said syst~ems, ~ .~
¦I The prior art contains electronic engine control I :
25 iI circuits which utilize an integrator ~or providing a reference :~- 3'. : - - I
. .~ . . ;
'',. '.: . I .
, `
., .
':
lO~lZ~;:
signal indicative of engine crankshaft position~ the'integrator Il being reset at predetermined engine crank angles.' For an elght ¦ cylinder engine the integrator is typically reset at 90 ¦! intervals. The i.ntegrator output is compared ~gainst a desired ¦ timing signal and when a predetermined relationshlp between the two occurs, an engine timing control signal is given.
Because the desired timing signal is a function of one or more parameters useful in controlling the engine, the engine angle~
or timing, of.the engine timing control signal is thereby controlled' in'accordance with these input parameters.
. The present invention is directed toward a novel engine control and novel circuitry ~or engine control which utilizes . ~ an integrator which is reset at predetermined engine crank ' . angles. Attempts to adapt prior art integrators to a four cylinder engine have enc-ountered a noticeable deterioration ¦l ln accuracy. Once source of this inaccuracy is the longer ; ~ duration of ~the integrator period. For example~ in going from ¦ an eight cylinder to a four cylinder system, the period of : I an integrator sawtooth wa~e~orm increases from 90 to 180'.
; 20 I In a closed-loop type system (for example:as shown in U. S.
. Patènt 3,885,534 assigned to the same assignee as the present application) inaccuracies are observed partlcularly under transient conditions because of associated time constants.
Such problems are accentuated in a four cylinder engine~because . Z5 ¦ of its more dynamic response.
J ~ I rhe present. invention provides an improvement , l~j 1i li ' ' '' _ _ 2 -. "', ' . ~:' ~09:~9;~
whereby thes~ inaccurac:ies clre greatly attenuated or even eliminated entirely thereby promotin~ accuracy in the timlng function. While the present invention is particularly well suited for a four cylinder engine, it will be appreciated that the principles disclosed herein anay be applied to other engine configurations.
The invention is used in an electronic engine control system wherein an engine control signal is generated in controlled relation to the rotational position of the engine crankshaft. The invention relates to the combination comprising: first means providing an alternating reference waveform having a period corresponding to a given crankshaft rotational range and within each period two half cycles of essentially equal duration; second means comprising an integrator for generating an output ramp function;
third means coupling the first means and the second means for resetting the integrator every half-cycle of the reference waveform; fourth means providing a ., .
" 20 signal whose value represents a crankshaft rotational position which is a function of at least one parameter useful in controlling the engine; fifth means coupled ` with the second means and ~he fourth means for comparing -; the last mentioned signal and the output ramp function and producing the engine control signal when a ~ predetermined relationship between the two occurs; and .. sixth means coupled with the first means and the fifth .' means for preventing the engine control signal from .. being given during alternate half-cycles of the reference ~ "
i~ 30 waveform.
. . .
~' mb/~o - 3 -~ ,~
~091~92 The invention is disclosed in connection with the accompanying drawings whlch illustrate a preEerred embodiment o~ the present invention according to the best mode presently contemplated in carrying out the invention.
BRIEF DESCRIPTION OF TIIR DRAWINGS
Figure 1 is an electrical schematic diagram of an engine control system embodying principles of the present invention.
Figure 2 is a diagram illustrating several waveforms (not necessarily to scale) at selected points of thecircuit of Fig. 1 which are useful in explaining the circuit operation.
DESCRIPTION OF THE PREFERRED EMBODIMENT
An illustrative electronic engine control circuit 10 embodying principles of the present invention is disclosed by way of example for a four cylinder engine configuration in an electronlc spark timing control system. Each of the cylinders fires once per -720 of crankshaft revolution whereby there are four firings per 720 . Circuit 10 shown in Fig. 1 comprises a pick-up device 12, an integrator 14, a comparator ` stage 16, an ignition stage 18, resetting and blanking : circuitry ~ mb/~o - 3a -1(~91~9'~
20 an(l tl-~ usllal ignition coil, driver, distributor, and spark plugs sllown generally at 22. The pick-llp device 12, which is illustrated by way of example as a Hall type device, is energi~ed from the B+ power supply and is operatively coupled with the engine crankshaft 24 to produce an output at line 36 in the form of a square wave signal like that shown by way of illustration at the top of Fig. 2. For the example, the output signal waveform has a period corresponding to 180 of crankshaft rotation (i.e. 720/4) and each period is composed of two equal half cycles corresponding to 90 of crankshaft rotation. The resetting and blanking circuitry 20 operatively couples pick-up device 12, integrator 14 and comparator stage 16.
Integrator 14 comprises an integrati~g capacitor 56 and other circuitry to generate a linear output voltage Q
ramp. An example of appropriate circuitry for the integrator is disclosed in U.S. Patent 3,885,534 and also in U.S. Patent 4,182,311, both of which are assigned to the same assignee as the present application. The integrating capacitor 56 is reset at predetermined engine crank angles whereby a periodic output ramp signal, which may take the form of a sawtooth waveform, is developed by the integrator. In the integrator circuits of the referenced patents, the peak amplitude of the integrator is closed-loop regulated whereby a sawtooth having a period equal to 720tN, N being the number of ~; engine cylinders, is generated so that under non-transient :
~ engine speed conditions the amplitude of the sawtooth at any ,', .
.
mb/c-)~
~`,' - ' ~ ' .
~ll 10~
instant of time :is representative of the instantaneous engine cranlcshaft angular position. Resetting Or the integrator is ¦ accomplished by switching a transistor 26 into conduction for a ¦ brief instant of time at predetermined engine crankshaft I positions to discharge accumulated charge on capacitor 56. This reset circuitry also includes a transistor 28, resistor 30, 32, and a capacitor 34 connected as illustrated. If it is assumed that the output signal waveform at line 36 is high, capacitor 34 Is fully charged, and transistor 28 conducts by virtue of the base :current supplied through resistor 32. With transistor 28 conductlng, transistor 26 is held nonconducting. When the square ~ave signal at line 36 switches from high to low, the negative-going edge momentarily couples the charge on capacitor 3ll as ~ negative spike to the base of translstor 28 thereby sharply cuttlng off this transistor. Correspondingly, transistor 26 switches into conduction to discharge capacitor 56. The . I time constant defined by capacitor 34 and resistor 32 is such that capacitor 34 quickly -charges to produce a positive volt-age at the base of transistor 28 thereby returning this transis-tor to conduction and hence cutting off transistor 26. The time constant is such that the resetting occurs within a very small angular range of crankshaft rotation even at maximum crankshaft ¦ speed. The next transition of the square wave from low to high ; serves to fully recharge capacitor 34 so that the next negative-going transition can cause the next reset. In this manner negative_going transitions of the square wave signal at line 36 are coupled through capacitor 34 whereby the integrator is reset by each negative-going transition of the square wave.
Ii 1, I' _ 5_ 1 1091Z~Z
l' l !! Circuit 20 comprises additional clrcuitry which both 1~ resets the integrator on each positlve-going edge of the jl square wave and also provides the blanking feature of the present invention. This circuitry includes a series voltage ~ divider comprising series connected resistors 38, 4Q and 42 I connected across the B+ supply, a transistor 44, a resistor 45 and capacitor 46. Resistor 45 connects the collector of transistor 44 to the positive terminal of the B~ supply, and ¦. capacitor 46, the collector of transistor 44 to the base of tr.ansistor 28; The :junction of resistors 38 and 40 connects : ~ to.the output of pick-up 12 at line 36. The base of ; tr.ansistor 44 connects to the junction of resistors 40 and 42.
. . 1 This arrangement provides at the collector of transistor 44 . I (i.e., at :line 54) a square wave signal,.like the second wave-¦ form shbwn in Fig. 2, which is inverted from the signal ¦ waveform at line 36. Capacitor 46 couples the negative-going edge of the line 54 signal waveform to the base of transistor .
.~ 1 28 so that .transistor 28 is momentarily switched out of . ¦ conduction in response to each negative-going edge of the j llne 54 waveform to reset integrator 14. Thus, it will be I recognized that the integrator is reset in response to both .
:: ¦ the positi.ve-going and the negative-going edges of-~-he line 36 .. I waveform signal, in other words, every 90 of crankshaft rota-.~ ~ tion. The third ~aveform shown in Fig. 2 illustrates the signal which appears at line 52 (i.e., the base of transistor 28 ¦I for resetting the integrator at 90 crankshaft intervals.
! Radio frequency filter capacitors 48 and 50 are connected as - 1l illustrated.
j, , . '1.
l(~91Z9;~
Tlle blankillg feature is provided by coupling the collector of transistor 44 ~hrough a diode 60 to a line 58 which connects the integrator output to one input of comparator stage 16. So that the blanking feature of the present invention may be better explalned, let it be assumed for the moment that the cathode of diode 60 is disconnected from line 58 so that blanking is absent.
The fourth waveform of Fig. 2 illustrates the sawtooth ; integrator output signal which appears under this condition. Absent blanking, the sawtooth has a period of 90 and a spark timing signal would be given once per period of the unblanked sawtooth instead of at the correct 180 intervals.
Now let it be assumed that diode 60 is again connected to line 58 so that blanking is present. The fifth waveform of Fig. 2 illustrates the integrator output signal with blanking. This waveform is a blanked sawtooth waveform wherein alternate cycles of the integrator sawtooth output are blanked. This blanked 20 sawtooth waveform has a period of 180 so that a spark firing signal is given at the correct interval of once per period of the blanked sawtooth. When transistor 44 is nonconducting, diode 60 is forward biased through resistor 45 to the positive terminal of the B+ supply so that the potential at line 58 is forced to slightly above that of the peak of the sawtooth waveform. When ; transistor 44 is conducting, diode 60 is reversed biased so that the potential at line 58 follows the sawtooth.
In this way the signal waveform shown at the bottom of Fig. 2 is developed at line 58. Thus spark firing is prevented during alternate half-cycles of the pick-up square wave.
' mb/c~,~/ ~ 7 109~Z~
Stated dif~erently, firing is permitted only between consecutive pairs of resettings of the integrator.
Comparator stage 16 comprises a comparator 62, a capacitor 64, and a plurality of three resistors 66, 68 and 70, all of which are connected in circuit as illustrated. A
desired spark timing signal derived from one or more parameters useful in controlling spark timing is supplied via resistor 68 to the non-inverting input o~ comparator 62, and the bianked waveform at line 58 is supplied through resistor 66 to the inverting input of comparator 62. The fifth waveform of Fig.
~ BACKGROUND AND SUMMARY OF THE INVRNTION ~ ¦
: ~ - This invention pertains generally to electronic eng~ne ¦ .
control Systems and specifically to a novel electronic circuit for said syst~ems, ~ .~
¦I The prior art contains electronic engine control I :
25 iI circuits which utilize an integrator ~or providing a reference :~- 3'. : - - I
. .~ . . ;
'',. '.: . I .
, `
., .
':
lO~lZ~;:
signal indicative of engine crankshaft position~ the'integrator Il being reset at predetermined engine crank angles.' For an elght ¦ cylinder engine the integrator is typically reset at 90 ¦! intervals. The i.ntegrator output is compared ~gainst a desired ¦ timing signal and when a predetermined relationshlp between the two occurs, an engine timing control signal is given.
Because the desired timing signal is a function of one or more parameters useful in controlling the engine, the engine angle~
or timing, of.the engine timing control signal is thereby controlled' in'accordance with these input parameters.
. The present invention is directed toward a novel engine control and novel circuitry ~or engine control which utilizes . ~ an integrator which is reset at predetermined engine crank ' . angles. Attempts to adapt prior art integrators to a four cylinder engine have enc-ountered a noticeable deterioration ¦l ln accuracy. Once source of this inaccuracy is the longer ; ~ duration of ~the integrator period. For example~ in going from ¦ an eight cylinder to a four cylinder system, the period of : I an integrator sawtooth wa~e~orm increases from 90 to 180'.
; 20 I In a closed-loop type system (for example:as shown in U. S.
. Patènt 3,885,534 assigned to the same assignee as the present application) inaccuracies are observed partlcularly under transient conditions because of associated time constants.
Such problems are accentuated in a four cylinder engine~because . Z5 ¦ of its more dynamic response.
J ~ I rhe present. invention provides an improvement , l~j 1i li ' ' '' _ _ 2 -. "', ' . ~:' ~09:~9;~
whereby thes~ inaccurac:ies clre greatly attenuated or even eliminated entirely thereby promotin~ accuracy in the timlng function. While the present invention is particularly well suited for a four cylinder engine, it will be appreciated that the principles disclosed herein anay be applied to other engine configurations.
The invention is used in an electronic engine control system wherein an engine control signal is generated in controlled relation to the rotational position of the engine crankshaft. The invention relates to the combination comprising: first means providing an alternating reference waveform having a period corresponding to a given crankshaft rotational range and within each period two half cycles of essentially equal duration; second means comprising an integrator for generating an output ramp function;
third means coupling the first means and the second means for resetting the integrator every half-cycle of the reference waveform; fourth means providing a ., .
" 20 signal whose value represents a crankshaft rotational position which is a function of at least one parameter useful in controlling the engine; fifth means coupled ` with the second means and ~he fourth means for comparing -; the last mentioned signal and the output ramp function and producing the engine control signal when a ~ predetermined relationship between the two occurs; and .. sixth means coupled with the first means and the fifth .' means for preventing the engine control signal from .. being given during alternate half-cycles of the reference ~ "
i~ 30 waveform.
. . .
~' mb/~o - 3 -~ ,~
~091~92 The invention is disclosed in connection with the accompanying drawings whlch illustrate a preEerred embodiment o~ the present invention according to the best mode presently contemplated in carrying out the invention.
BRIEF DESCRIPTION OF TIIR DRAWINGS
Figure 1 is an electrical schematic diagram of an engine control system embodying principles of the present invention.
Figure 2 is a diagram illustrating several waveforms (not necessarily to scale) at selected points of thecircuit of Fig. 1 which are useful in explaining the circuit operation.
DESCRIPTION OF THE PREFERRED EMBODIMENT
An illustrative electronic engine control circuit 10 embodying principles of the present invention is disclosed by way of example for a four cylinder engine configuration in an electronlc spark timing control system. Each of the cylinders fires once per -720 of crankshaft revolution whereby there are four firings per 720 . Circuit 10 shown in Fig. 1 comprises a pick-up device 12, an integrator 14, a comparator ` stage 16, an ignition stage 18, resetting and blanking : circuitry ~ mb/~o - 3a -1(~91~9'~
20 an(l tl-~ usllal ignition coil, driver, distributor, and spark plugs sllown generally at 22. The pick-llp device 12, which is illustrated by way of example as a Hall type device, is energi~ed from the B+ power supply and is operatively coupled with the engine crankshaft 24 to produce an output at line 36 in the form of a square wave signal like that shown by way of illustration at the top of Fig. 2. For the example, the output signal waveform has a period corresponding to 180 of crankshaft rotation (i.e. 720/4) and each period is composed of two equal half cycles corresponding to 90 of crankshaft rotation. The resetting and blanking circuitry 20 operatively couples pick-up device 12, integrator 14 and comparator stage 16.
Integrator 14 comprises an integrati~g capacitor 56 and other circuitry to generate a linear output voltage Q
ramp. An example of appropriate circuitry for the integrator is disclosed in U.S. Patent 3,885,534 and also in U.S. Patent 4,182,311, both of which are assigned to the same assignee as the present application. The integrating capacitor 56 is reset at predetermined engine crank angles whereby a periodic output ramp signal, which may take the form of a sawtooth waveform, is developed by the integrator. In the integrator circuits of the referenced patents, the peak amplitude of the integrator is closed-loop regulated whereby a sawtooth having a period equal to 720tN, N being the number of ~; engine cylinders, is generated so that under non-transient :
~ engine speed conditions the amplitude of the sawtooth at any ,', .
.
mb/c-)~
~`,' - ' ~ ' .
~ll 10~
instant of time :is representative of the instantaneous engine cranlcshaft angular position. Resetting Or the integrator is ¦ accomplished by switching a transistor 26 into conduction for a ¦ brief instant of time at predetermined engine crankshaft I positions to discharge accumulated charge on capacitor 56. This reset circuitry also includes a transistor 28, resistor 30, 32, and a capacitor 34 connected as illustrated. If it is assumed that the output signal waveform at line 36 is high, capacitor 34 Is fully charged, and transistor 28 conducts by virtue of the base :current supplied through resistor 32. With transistor 28 conductlng, transistor 26 is held nonconducting. When the square ~ave signal at line 36 switches from high to low, the negative-going edge momentarily couples the charge on capacitor 3ll as ~ negative spike to the base of translstor 28 thereby sharply cuttlng off this transistor. Correspondingly, transistor 26 switches into conduction to discharge capacitor 56. The . I time constant defined by capacitor 34 and resistor 32 is such that capacitor 34 quickly -charges to produce a positive volt-age at the base of transistor 28 thereby returning this transis-tor to conduction and hence cutting off transistor 26. The time constant is such that the resetting occurs within a very small angular range of crankshaft rotation even at maximum crankshaft ¦ speed. The next transition of the square wave from low to high ; serves to fully recharge capacitor 34 so that the next negative-going transition can cause the next reset. In this manner negative_going transitions of the square wave signal at line 36 are coupled through capacitor 34 whereby the integrator is reset by each negative-going transition of the square wave.
Ii 1, I' _ 5_ 1 1091Z~Z
l' l !! Circuit 20 comprises additional clrcuitry which both 1~ resets the integrator on each positlve-going edge of the jl square wave and also provides the blanking feature of the present invention. This circuitry includes a series voltage ~ divider comprising series connected resistors 38, 4Q and 42 I connected across the B+ supply, a transistor 44, a resistor 45 and capacitor 46. Resistor 45 connects the collector of transistor 44 to the positive terminal of the B~ supply, and ¦. capacitor 46, the collector of transistor 44 to the base of tr.ansistor 28; The :junction of resistors 38 and 40 connects : ~ to.the output of pick-up 12 at line 36. The base of ; tr.ansistor 44 connects to the junction of resistors 40 and 42.
. . 1 This arrangement provides at the collector of transistor 44 . I (i.e., at :line 54) a square wave signal,.like the second wave-¦ form shbwn in Fig. 2, which is inverted from the signal ¦ waveform at line 36. Capacitor 46 couples the negative-going edge of the line 54 signal waveform to the base of transistor .
.~ 1 28 so that .transistor 28 is momentarily switched out of . ¦ conduction in response to each negative-going edge of the j llne 54 waveform to reset integrator 14. Thus, it will be I recognized that the integrator is reset in response to both .
:: ¦ the positi.ve-going and the negative-going edges of-~-he line 36 .. I waveform signal, in other words, every 90 of crankshaft rota-.~ ~ tion. The third ~aveform shown in Fig. 2 illustrates the signal which appears at line 52 (i.e., the base of transistor 28 ¦I for resetting the integrator at 90 crankshaft intervals.
! Radio frequency filter capacitors 48 and 50 are connected as - 1l illustrated.
j, , . '1.
l(~91Z9;~
Tlle blankillg feature is provided by coupling the collector of transistor 44 ~hrough a diode 60 to a line 58 which connects the integrator output to one input of comparator stage 16. So that the blanking feature of the present invention may be better explalned, let it be assumed for the moment that the cathode of diode 60 is disconnected from line 58 so that blanking is absent.
The fourth waveform of Fig. 2 illustrates the sawtooth ; integrator output signal which appears under this condition. Absent blanking, the sawtooth has a period of 90 and a spark timing signal would be given once per period of the unblanked sawtooth instead of at the correct 180 intervals.
Now let it be assumed that diode 60 is again connected to line 58 so that blanking is present. The fifth waveform of Fig. 2 illustrates the integrator output signal with blanking. This waveform is a blanked sawtooth waveform wherein alternate cycles of the integrator sawtooth output are blanked. This blanked 20 sawtooth waveform has a period of 180 so that a spark firing signal is given at the correct interval of once per period of the blanked sawtooth. When transistor 44 is nonconducting, diode 60 is forward biased through resistor 45 to the positive terminal of the B+ supply so that the potential at line 58 is forced to slightly above that of the peak of the sawtooth waveform. When ; transistor 44 is conducting, diode 60 is reversed biased so that the potential at line 58 follows the sawtooth.
In this way the signal waveform shown at the bottom of Fig. 2 is developed at line 58. Thus spark firing is prevented during alternate half-cycles of the pick-up square wave.
' mb/c~,~/ ~ 7 109~Z~
Stated dif~erently, firing is permitted only between consecutive pairs of resettings of the integrator.
Comparator stage 16 comprises a comparator 62, a capacitor 64, and a plurality of three resistors 66, 68 and 70, all of which are connected in circuit as illustrated. A
desired spark timing signal derived from one or more parameters useful in controlling spark timing is supplied via resistor 68 to the non-inverting input o~ comparator 62, and the bianked waveform at line 58 is supplied through resistor 66 to the inverting input of comparator 62. The fifth waveform of Fig.
2 illustrates comparison between the desired spark timing signal and the blanked sawtooth signal whereby an output signal is given at the output of comparator stage 16 each time that I the desired spark timing signal intercepts the blanked signal waveform. Accordingly, it can be seen that the firing occurs once-per period of the blanked sawtooth waveform at an engine crank angle which is determined by the desired spark timing signal magnitude. In contrast, the fourth waveform (which illustrates diode 60 disconnected from the circuit) demonstrates that absent blanking the firlng would oc^ur twice per period -of the s~uare wave pick-up signal.
An important advantage of the presen~ invention is that the slope of the ramp signal is increased from what it would be ln a syste~ ere the sawtooth has a perlod of lôO'. Th1s ``' ' ~
,.' l :
lO9iZ~
¦means that a sharper intercept is provided thereby yieldlng lmproved acc~racy in the timing than would otherwise be available.
!A further advantage obtains where a closed-loop type integrator .
¦is used because the time constants associated with the integrator Ido not have to be compromised. .
The remain~er of the circuit:comprises an ignition ~iring stage including a pair of transistors 72, 74, a number .~ o~ resistors 76, 78, 80, 82, 84, and 86, a capacitor 88~ and a diode 90. A lock-out circuit including a transistor 92 and a ~o resistor 94 is provided and all these components are connected .
. as illustrated in the drawing. The output signal given by comparatbr stage 16 is in the form o~ a negative-going pulse coupled through resistor 86 and capacitor 88 to reverse bias .diode 90 and cut-off transistor 72. The rise in collector .
voltage at transistor 72 is supplied through resistor 84 to I switch transistor 74 into conduction and thereby rire the .
¦ignition coil driver stage (not shown) which in turn fires the .
lgnition coil to deliver the spark via the distributor.to the appropriate spark plug... The rise in collector voltage at . .
. 20 transistor 72 renders transistor 92 conductive during an anti-.. - . dwell timing.cycle. The duration o~ conduction Or transistor . 72 is established via the anti-dwell timing characteristics o~
resistors 76, 78, and capacitor 88 as well as the Vspeed signal which is an analog speed signal which may be derived ~rom integrator 14. This endows the circult with a speed rclated ,,.,, :.
,` . ', .: - li g .
.
:
109i~9Z
anti-~wel~ characteristic and is desirable in securing best performance. When transistor 72 switches into conductlon, tran-sistor 92 is cut off and the circuit transiently returns to lts initial condition to await the next firing pulse from comparator stage 16.
While one specific preferred embodiment of the -invention has been disclosed, its principles are applicable to other configurations. Other types of pick-ups and integrators may be used. Other than four cylinder engines can utilize the invention. The invention can be employed in other engine ti~ing ¦ control functions than spark timing, for example, ~uel in~ector timing, Thus, there has been presented a novel and versa~ile engine control and circuit.
:': ' , . ' , ' ..
. , .
'~ ' ' . ~' ll I
. , - '.
- 10- ''
An important advantage of the presen~ invention is that the slope of the ramp signal is increased from what it would be ln a syste~ ere the sawtooth has a perlod of lôO'. Th1s ``' ' ~
,.' l :
lO9iZ~
¦means that a sharper intercept is provided thereby yieldlng lmproved acc~racy in the timing than would otherwise be available.
!A further advantage obtains where a closed-loop type integrator .
¦is used because the time constants associated with the integrator Ido not have to be compromised. .
The remain~er of the circuit:comprises an ignition ~iring stage including a pair of transistors 72, 74, a number .~ o~ resistors 76, 78, 80, 82, 84, and 86, a capacitor 88~ and a diode 90. A lock-out circuit including a transistor 92 and a ~o resistor 94 is provided and all these components are connected .
. as illustrated in the drawing. The output signal given by comparatbr stage 16 is in the form o~ a negative-going pulse coupled through resistor 86 and capacitor 88 to reverse bias .diode 90 and cut-off transistor 72. The rise in collector .
voltage at transistor 72 is supplied through resistor 84 to I switch transistor 74 into conduction and thereby rire the .
¦ignition coil driver stage (not shown) which in turn fires the .
lgnition coil to deliver the spark via the distributor.to the appropriate spark plug... The rise in collector voltage at . .
. 20 transistor 72 renders transistor 92 conductive during an anti-.. - . dwell timing.cycle. The duration o~ conduction Or transistor . 72 is established via the anti-dwell timing characteristics o~
resistors 76, 78, and capacitor 88 as well as the Vspeed signal which is an analog speed signal which may be derived ~rom integrator 14. This endows the circult with a speed rclated ,,.,, :.
,` . ', .: - li g .
.
:
109i~9Z
anti-~wel~ characteristic and is desirable in securing best performance. When transistor 72 switches into conductlon, tran-sistor 92 is cut off and the circuit transiently returns to lts initial condition to await the next firing pulse from comparator stage 16.
While one specific preferred embodiment of the -invention has been disclosed, its principles are applicable to other configurations. Other types of pick-ups and integrators may be used. Other than four cylinder engines can utilize the invention. The invention can be employed in other engine ti~ing ¦ control functions than spark timing, for example, ~uel in~ector timing, Thus, there has been presented a novel and versa~ile engine control and circuit.
:': ' , . ' , ' ..
. , .
'~ ' ' . ~' ll I
. , - '.
- 10- ''
Claims (6)
1. In an electronic engine control system wherein an engine control signal is generated in controlled relation to the rotational position of the engine crankshaft, the combination comprising:
first means providing an alternating reference wave-form having a period corresponding to a given crankshaft rotational range and within each period two half cycles of essentially equal duration;
second means comprising an integrator for generating an output ramp function;
third means coupling said first means and said second means for resetting said integrator every half-cycle of said reference waveform;
fourth means providing a signal whose value repre-sents a crankshaft rotational position which is a function of at least one parameter useful in controlling the engine;
fifth means coupled with said second means and said fourth means for comparing said last-mentioned signal and said output ramp function and producing said engine control signal when a predetermined relationship between the two occurs; and sixth means coupled with said first means and said fifth means for preventing said engine control signal from being given during alternate half-cycles of said reference waveform.
first means providing an alternating reference wave-form having a period corresponding to a given crankshaft rotational range and within each period two half cycles of essentially equal duration;
second means comprising an integrator for generating an output ramp function;
third means coupling said first means and said second means for resetting said integrator every half-cycle of said reference waveform;
fourth means providing a signal whose value repre-sents a crankshaft rotational position which is a function of at least one parameter useful in controlling the engine;
fifth means coupled with said second means and said fourth means for comparing said last-mentioned signal and said output ramp function and producing said engine control signal when a predetermined relationship between the two occurs; and sixth means coupled with said first means and said fifth means for preventing said engine control signal from being given during alternate half-cycles of said reference waveform.
2. The combination of claim 1 wherein said sixth means comprises means for blanking said output ramp function during said alternate half-cycles of said reference waveform.
3. The combination of claim 1 wherein said first means comprises means providing said alternating waveform as a square wave signal.
4. In an electronic engine control system wherein an engine control signal is given in controlled relation to the rotational position of the engine crankshaft, the combination comprising:
first means comprising an integrator providing a ramp output signal;
second means operatively coupling said crankshaft and said first means for resetting said integrator at predetermined engine crankshaft rotational positions;
third means providing a signal whose value represents a crankshaft rotational position which is a function of at least one parameter useful in controlling the engine;
fourth means coupled with said first means and said third means for comparing said last-mentioned signal and said ramp output signal and producing said engine control signal when a predetermined relationship between the two occurs; and fifth means coupled with said second means and said fourth means for permitting said engine control signal to be given only between consecutive pairs of resettings of said integrator.
first means comprising an integrator providing a ramp output signal;
second means operatively coupling said crankshaft and said first means for resetting said integrator at predetermined engine crankshaft rotational positions;
third means providing a signal whose value represents a crankshaft rotational position which is a function of at least one parameter useful in controlling the engine;
fourth means coupled with said first means and said third means for comparing said last-mentioned signal and said ramp output signal and producing said engine control signal when a predetermined relationship between the two occurs; and fifth means coupled with said second means and said fourth means for permitting said engine control signal to be given only between consecutive pairs of resettings of said integrator.
5. The combination of claims 4 wherein said second means comprises means for resetting said integrator at uniform intervals of engine crankshaft rotation.
6. The combination of claim 4 wherein said fifth means comprises means for blanking said ramp output signal during intervals between the two resettings of each pair.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/752,490 US4156411A (en) | 1976-12-20 | 1976-12-20 | Engine timing control circuit |
| US752,490 | 1976-12-20 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1091292A true CA1091292A (en) | 1980-12-09 |
Family
ID=25026526
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA292,986A Expired CA1091292A (en) | 1976-12-20 | 1977-12-13 | Engine timing control circuit |
Country Status (8)
| Country | Link |
|---|---|
| US (1) | US4156411A (en) |
| AU (1) | AU3180177A (en) |
| CA (1) | CA1091292A (en) |
| DE (1) | DE2756211A1 (en) |
| FR (1) | FR2374529A1 (en) |
| GB (1) | GB1545040A (en) |
| IT (1) | IT1088745B (en) |
| SE (1) | SE430354B (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2446389A1 (en) * | 1979-01-12 | 1980-08-08 | Marchal Equipements Automobile | ELECTRONIC IGNITION DEVICE FOR AN INTERNAL COMBUSTION ENGINE |
| DE2927538C2 (en) * | 1979-07-07 | 1984-08-23 | Audi Nsu Auto Union Ag, 7107 Neckarsulm | Device for generating a reference signal corresponding to a specific working state of a four-stroke internal combustion engine |
| US4779214A (en) * | 1984-12-07 | 1988-10-18 | Toyata Jidosha Kabushiki Kaisha | System for detecting an engine speed in a multi-cylinder internal combustion engine |
| US5222022A (en) * | 1986-12-01 | 1993-06-22 | Woodward Governor Company | Method and apparatus for iterated determinations of sensed speed and speed governing |
| US5517962A (en) * | 1994-12-13 | 1996-05-21 | Outboard Marine Corporation | Variable timing ignition circuit including conditional ignition retarding |
| US6058908A (en) * | 1998-05-29 | 2000-05-09 | Autotronic Controls Corporation | Hall effect ignition |
| US9702298B2 (en) * | 2014-12-09 | 2017-07-11 | Ford Global Technologies, Llc | Diagnostic method for a compressor recirculation valve |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3596189A (en) * | 1969-02-18 | 1971-07-27 | Frank K Luteran | Noncontact shaft synchronizer |
| US3867916A (en) * | 1972-12-15 | 1975-02-25 | Volkswagenwerk Ag | Internal combustion engine ignition control system |
| US3885534A (en) * | 1973-08-15 | 1975-05-27 | Chrysler Corp | Electronic advance and retard control circuit |
| US3923030A (en) * | 1974-09-19 | 1975-12-02 | Frank Kenneth Luteran | Phase sensitive ignition timing system |
| US3991730A (en) * | 1975-01-30 | 1976-11-16 | Chrysler Corporation | Noise immune reset circuit for resetting the integrator of an electronic engine spark timing controller |
-
1976
- 1976-12-20 US US05/752,490 patent/US4156411A/en not_active Expired - Lifetime
-
1977
- 1977-12-13 CA CA292,986A patent/CA1091292A/en not_active Expired
- 1977-12-16 DE DE19772756211 patent/DE2756211A1/en not_active Ceased
- 1977-12-19 FR FR7738293A patent/FR2374529A1/en active Granted
- 1977-12-19 GB GB52803/77A patent/GB1545040A/en not_active Expired
- 1977-12-19 IT IT30914/77A patent/IT1088745B/en active
- 1977-12-19 SE SE7714419A patent/SE430354B/en not_active IP Right Cessation
- 1977-12-20 AU AU31801/77A patent/AU3180177A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| FR2374529B1 (en) | 1983-10-28 |
| AU3180177A (en) | 1979-06-28 |
| SE430354B (en) | 1983-11-07 |
| FR2374529A1 (en) | 1978-07-13 |
| IT1088745B (en) | 1985-06-10 |
| US4156411A (en) | 1979-05-29 |
| GB1545040A (en) | 1979-05-02 |
| DE2756211A1 (en) | 1978-06-22 |
| SE7714419L (en) | 1978-06-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4153019A (en) | Peak cylinder combustion pressure ignition spark timing system | |
| US4211194A (en) | Ignition system for internal combustion engines | |
| US3937193A (en) | Electronic ignition system | |
| US5694900A (en) | Knock control system for an internal combustion engine | |
| US4455989A (en) | Plasma ignition system for internal combustion engine | |
| US4131097A (en) | Ignition system for internal combustion engines | |
| US3202146A (en) | Static transistorized ignition system | |
| US3943896A (en) | Electronic control of spark advance and dwell | |
| US4085714A (en) | Electronic ignition timing adjusting system for internal combustion engine | |
| CA1109928A (en) | Ignition dwell circuit for an internal combustion engine | |
| CA1091292A (en) | Engine timing control circuit | |
| US3885534A (en) | Electronic advance and retard control circuit | |
| CA1080793A (en) | Electronic arrangement for controlling the ignition of an internal combustion engine | |
| US4284046A (en) | Contactless ignition system for internal combustion engine | |
| US6408820B1 (en) | Capacitor discharge engine ignition system with automatic ignition advance and/or minimum ignition speed control | |
| US5429103A (en) | High performance ignition system | |
| US3783850A (en) | Ignition advance circuit | |
| US4249494A (en) | Internal combustion engine ignition systems | |
| US4180023A (en) | Electronically-controlled fuel injection system for internal combustion engine having odd numbers of cylinders | |
| JPH0311421Y2 (en) | ||
| US4033272A (en) | Electronic ignition timing system for an internal combustion engine | |
| US4102310A (en) | Electronic circuit for use in a variety of engine control systems | |
| US3851636A (en) | Solid state ignition circuitry | |
| GB1598043A (en) | Electrically controlled fuel injection systems | |
| US4241708A (en) | Ignition spark timing circuit with switchable hysteresis |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |